Unreal is weird about this, and two Ambient Sound actors (with 3D sound attenuation) will often cancel each other out when both sounds play at once.
However, my work around is as follows:
- Place one Ambient Sound actor at your player start.
- Make sure your Ambient Sound actor has your sound attached.
- Make sure the radius of your Ambient Sound actor does not overlap with another Ambient Sound actor.
- You will need to repeat steps 1-3 will all your sound wave files so each sound file always works with your Ambient Sound actors. (Simply switching the sound file on the Ambient Sound actor should do.)
Explanation: Why does this work? If the camera is inside the Ambient Sound actor’s radius when the game starts, Unreal will load the sound file so it always plays with any Ambient Sound actor. It is probably a weird memory cache thing.)
If this doesn’t work try these extra measures:
Create a Sound Class to force loading…
Open your sound wave file, then create and assign a new Sound Class.
Open you new Sound Class and turn “Always Play” on.